Saw-crack punch



R. SPENCER SAW CRACK PUNCH April 5, 1927. 1,623,816

iled Nov. 6, 1925 I N VEN TOR.

J klofirz/ializ'e e ioelu'eg;

ATTORNEY.

PATENT OFFICE.

JOHN R. SPENCER, OF KINGSFORD, MICHIGAN-..

SAW-CRACK PUNCH.

Application filed November This invention relates to punch devices and pertains particularly to a punch designed particularly for use in stopping cracks in saw blades or strip steel.

The primary object of this invention is the provision, in a manner as hereinafter set forth, of a punch tool designed for punching strip steel or saw blades or denting the same to stop cracks which may have been started therein.

It is well known that saw blades or strip steel often develop cracks whichcontinue to increase in length until the blade or strip of steel has become broken in. half and therefore useless. If a punch .or dent is made in the body of the steel at the extremitiesof the crack, it will beprevented from going further and the tool will be saved for a longer useful life. y

The device embodying this invention is designed to impart such. dents to the saw blade body and is especially designed to be used by one man without inconvenience or trouble.

The final object of the invention is the provision, in a manner as hereinafter set forth, of a punch device of strong and du= rable, but simple construction, easy to handle and use, and inexpensive to manufacture.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming a part of this specification, with the understanding that the invention is not confined to any strict conformity with the showing of the drawings but may be changed and modified so long as such changes and modifications mark no material departure from the salient features of the invention as expressed in the appended claim.

In the drawings Figure 1 shows in side elevation, the device embodying this invention.

Figure 2 shows avertical sectional view of the same.

Figure 3 shows a top plan view of the device and,

Figure 4 shows a modified type of anvil for use in the instrument.

Referring now to the drawings in detail wherein like numerals of reference indicate corresponding parts throughout the several views, the numeral 1 indicates a handle stock which is here shown as round and having circumferentially extending ribbed serrated s, 1925. Serial No. 67,404.

bands 2 formed theron to enable the user of the tool touobtain a better grip upon the same.

The upper end of the hand grip l merges into the outer side of. one leg 3 of a substantially Urshaped. portion indicated generally by the numeral 4. As shown, the handle connects with the leg 3 at the free outer end thereof and extends at right angles from the outer face;

The portion or member t-is, as above stated, substantially U-shaped and the leg 3 thereof is relatively broad and the connecting yoke portion 5 is of the same width whereas the upper leg (S-tapers slightlytowards the outer end thereofland terminates in the sleeve 7 which, as shown, extends at right angles to the inner and outer faces of the leg 6 and has a central bore 8 formed therethrough. The upper end of the bore 8 is threaded as indicated-at 9..

Formed in the inner face of the lower leg 3, directly in alignment with the bore 8 through the sleeve lying thereover, is an annular recess 10 inwhich therev is adapted to fit an anvil 11, which anvil has the upper surface formed in the shape of a truncated cone 12, Formed through the side of the leg 3' is a threaded bore in which there is; screwed a set screw 13, the inner-end of which projects. into arecesslin the anvil 11 to secure the anvil in its, seat.

A bore 15 is formed through the longitudinal center of the hand grip l and opens into the recess 10 in which the anvil .11 seats. In event that the anvil is to be removed and has become fixed in its seat, an instrument can be extended through the bore 15 to force the anvil from its recess.

Extending through the bore 8 in the sleeve 7 is a punch indicated generally by the numeral 16 which punch comprises a head 17 which snugly tits in the passage 8 and a shank 18 of less diameter than the head and which extends through the sleeve at a substantial distance beyond the outer end thereof as shown. The inner end of the head 17 is formed to provide the inverted cone 19, the point or apex of which contacts with the center of the portion 12, of the anvil lllocated therebeneath.

Positioned about the shank 18 of the punch there is a coiled spring 20 which bears against the rear side of the head 17 as shown, and threaded into the bore 8 about the shank 18, is a retaining sleeve 21 engaging the threads 9 in the bore and bearing against the other end of the spring to place the same under the desired tension. The sleeve 21 is provided with the knurled head 22 by means of Which a firm grip can be obtained upon the sleeve to screw it into the passage 8 or out of the same as desired.

It will be seen that the punch 16, dueto the action of the spring 20 is always pressed against the truncated cone 12 of the anvil 11 and therefore the object to be dented or punched, when placed between the punch and anvil, will have the punch resting thereon at the desired point, before the blow is struck upon the end 23 of the shank, to punch the object.

The anvil 11, having the flat surface against which the punch point abuts, is adapted for use primarily upon thick or small gauge saws. When such saws are punched it is necessary to make a dent or punch upon both sides thereof. Vhen a thinner saw, or one of higher gauge is to be punched, there is substituted for the anvil 11 a pointed anvil such as that indicated by the numeral 24. This anvil has the base portion of the same diameter as the recess 10 into which it is seated and instead of having a truncated cone upper surface, a full cone 25 is formed and the apex of this cone is directly in alignment With the apex of the cone 19 of the punch, when this anvil is in position. A recess 26 is formed in the side of the anvil to receive the end of the set screw 13 which holds the anvil solidly in position. When using this anvil to punch thinner saws, a dent or punch is required on but one side.

In the use of this instrument, the user grasps the hand grip 1 holding the same with the free end directed toward his body and with the U-shaped portion 4- in upright position or with the free ends of the legs thereof directed upwardly. The saw to be punched is thenplaced between the legs 3 and 6 with the anvil directed against the point on-the blade in which the dent is to be made. A sharp blow is then given to the end 23 of the shank 18 to drive the pointed end of the punch into the metal of the saw.

From the foregoing description it will be readily seen that there has been provided a unique and easily handled instrui'nent or tool with which one man can dent or punch saw blades to. stop cracks which have begun to form therein.

lVhat I claim is A punch of the character described, comprising a substantially U-shaped member, one leg of said member having a longitudinally bored head formed transversely thereof, screw threads formed in the outer end of the bore of said head, a handle extending from the other leg of said member in alignment with said bored head, said handle having a longitudinally extending passage therethrough terminating in a recess, a punch comprising a head adapted to fit and move snugly in said bore and a shank carried by the head and extending beyond the outer end of the bore, a. coiled spring surrounding said shank and bearing against the back of said head, a sleeve threaded into the bore and bearing at the inner end against said spring, an anvil positioned in said recess, and a securing element extended into the side of the recessed leg into said recess to engage said anvil.

In testimony whereof, I aflix my signature hereto.

JOHN R. SPENCER. 

